Sign up to receive email updates, action alerts, health tips, promotions to support our work and more from EWG. You can opt-out at any time. [Privacy]


The Specter of "Super Germs"

July 17, 2008

Pesticide in Soap, Toothpaste and Breast Milk - Is It Kid-Safe?: The Specter of "Super Germs"

Scientists and doctors have raised many and frequent concerns about the potential development of antibiotic-resistant bacteria as a consequence of the overuse of triclosan (Levy 2001; Tan 2002; Aiello 2005). In a recent publication, the American Medical Association (AMA) notes that "[s]tudies also suggest that acquired resistance to the antimicrobial agents used in consumer products may predispose bacteria to resistance against therapeutic antibiotics, but further research is needed. Considering available data and the critical nature of the antibiotic-resistance problem, it is prudent to avoid the use of antimicrobial agents in consumer products" (Tan 2002).

Researchers have not yet proven conclusively that triclosan-resistant bacteria are developing in homes and hospitals, but this is an all too common phenomenon for pesticides and antibiotics in general. Whenever bacteria are deluged with a pesticide or drug, mutant bacteria resistant to the pesticide have a selective growth advantage. Those resistant bacteria then proliferate and can become the dominant form. In recent years we have witnessed entire lines of drugs or pesticides lose effectiveness, leaving everybody more vulnerable to infection.

The phenomenon of reduced susceptibility is already apparent in several cases involving triclosan in laboratory studies (McMurry 1998; Chuanchuen 2001). These studies' identification of the triclosan-resistant bacterial enzyme suggests that resistance to triclosan may develop more readily than to other antibacterial agents (Heath 2000). In addition, exposing specific bacterial strains to triclosan appears to result in selection favoring bacteria that are resistant to multiple antibiotics (Chuanchuen 2001). These findings have led AMA to suggest that antibacterial products not be used in homes for fear that they would perpetuate the resistant strains of bacteria (Tan 2002).

Some scientists also suggest widespread household use of triclosan may result in increased risk of allergy in children, an unintended consequence potentially caused by alterations to a developing body's natural microbial community following chronic exposure to the pesticide, and resulting in immune system abnormalities (Levy 2001). While some advocate that triclosan plays a valuable role in the care of vulnerable patients in the hospital setting, even medical uses of triclosan may be called into question. A recent investigation of sutures coated with the pesticide, marketed as a means of preventing infection, found more complications developed for wounds closed with the triclosan-treated materials than for those closed with ordinary sutures (Deliaert 2008).

In summary, the best available science, joined with everything we have learned about pesticides, points to a single conclusion: Unless the use of triclosan is absolutely warranted, as it may be in specific clinical settings, our best bet is not to use it. Indiscriminate addition of triclosan to home-use products is unnecessary, does not appear to provide any additional protection from infection, and may breed triclosan-resistant "super germs." Let's act with common sense and save this potent chemical for times when we really need it.